The present invention relates generally to catamaran-like vessels in which a superstructure or platform is supported on a pair of hulls, and is particularly directed to a vessel designed to plane on the watersurface at speed.
Vessels capable of planing on the watersurface are able to reach high speeds in view of the fact that the vessel is lifted up out of the water to reduce skin friction and wavemaking drag. In some boats, leg-type retractable hydrofoils are employed at the front end of the boat to lift it up out of the water at speed. Other designs employ ski-like structures. However, these vessels have hulls which rest in the water at preplaning speeds and are therefore subject to relatively high drag at such speed. A wave making "drag hump" occurs as such vessels start to lift out of the water, with the bow rising and the stern dropping, and increased power will be required to achieve planing speeds.
In catamaran-like vessels having twin hulls supporting a platform or superstructure, it is known to utilize submerged, buoyant hulls to support the superstructure on struts above the waterline. Such a structure is described in my U.S. Pat. No. 3,866,557. This structure employs rectangular shape hulls for supporting the boat platform. This produces increased stability. The structure is designed so that the waterline at rest lies at about the mid-point of the struts, dependent on the boat load. Although not specifically designed for this purpose, the vessel described in this reference is capable of planing on the lower hulls at high speed with sufficient power. However, this structure is not particularly efficient for planing purposes, and has to lift a substantial distance out of the water to plane.